This invention relates to telephone answering systems, such as telephone answering machines and voice mail platforms.
Telephone answering machines and voicemail platforms provide a very useful service. In the case of a telephone answering machine, a caller can leave when the called party is not present. The called party typically retrieves messages by interacting with the physical user-interface of the answering machine itself. In the case of voice mail platforms, it allows a caller to leave a message when the called party is busy with another call as well as when the called party is not present. The called party typically retrieves the messages via the telephone instrument that is associated with the telephone number dialed by the party that left the message.
At times, it is desirable to retrieve messages from some other location. Recognizing this fact, the voicemail platform permits a user to call the platform from anywhere, identify the voicemail box (which is the number called by the party that left the message) enter a password, and retrieve the messages. Similarly, most telephone answering machines are adapted to accept a triggering code from a remote device, which diverts the telephone answering machine from a message-taking mode to a message-retrieval mode. Alas, the above-described approach to remote message retrieval is machines, or in connection with accounts on a voicemail platform, are typically quite short (perhaps two to six digits long) and, therefore, it takes an interloper a relatively short time to overcome this security hurtle.
A more severe problem exists when the voice mail is played out over an insecure data network (e.g., the Internet) or, worse yet, over wireless link, since an interloper can simply eavesdrop on the passing information.